Ink feed system for printing machines



y 3, 1955 c. H. MORHARD T 2,707,434

INK FEED SYSTEM FOR PRINTING MACHINES Filed llay 23, 1952 3 Sheets-Sheet 1 INVENTOR.

ATTORNEYS.

y 3, 1955 c. H. MORHARDT 2,707,434

INK FEED SYSTEM FOR PRINTING MACHINES Filed lay 23, 1952 3 Sheets-Sheet 2 INVENTOR.

ATTORNEKS.

M y 3, 5 c. H. MORHARDT 2,707,434

INK FEED SYSTEM FOR PRINTING MACHINES Filed May 23, 1952 3 Sheets-Sheet 3 INVENTOR.

ATTORNEKS.

United States Patent ffice 2,707,434 l mented May 3, Edd-5 INK FEED SYSTEB'I FOR PRINTING MACHINES Charles H. Morhardt, Baldwin, N. Y., assignor to A. B. Dick Company, Niles, Ill., a corporation of Illinois Application May 23, 1952, Serial No. 289,594

10 Claims. (Cl. 101-4350) This invention relates to a new and improved inking system and more particularly to a method and apparatus for supplying ink composition in continuous fashion to rotatable inking rollers of a printing or duplicating machine.

There are many features in common in inking systems used in the production of copy by letter press printing or by lithographic printing or in other printing systems wherein ink is transferred for the production of copy. In general, press systems of the types described comprise an ink fountain having a fountain roller operative therein to convey a predetermined amount of ink about the peripheral surface thereof. ink is transferred by a doctor roller which rocks back and forth between the fountain. roller and the first of a series of inking rollers which rotate in operative engagement with laterally re ciprocating spreader rollers to distribute the applied ink uniformly over the surface before the ink composition reaches the last roller in contact with the printing plate which takes off ink in amounts necessary to meet copy requirements.

Elaborate mechanism including doctor blades with screw adjustments and the like are provided in the ink fountain to measure the quantity of ink supplied to the fountain roller in the attempt to provide amounts calculated as precisely as possible to maintain copy take-off requirements for the production of copy of good quality.

Systems of the type described, representing present practice, are subject to a number of objections. Since it is desirable to make use of reasonably fresh ink having the desired consistency and since it is imperative for good operation to use ink which is reasonably free of dust, dirt, lint or other foreign matter, it becomes common practice to discard the ink composition remaining in the fountain at the end of the days work and to clean out the fountain and parts associated therewith in the ink feed system. This involves not only considerable waste of ink composition but the process is frowned upon by operators because it is dirty and time-consuming. Further, before introducing a new supply of ink to the ink fountain, it is necessary to remove the viscous composition from an open container and to spatulate the ink in the ink fountain in order to' secure proper distribution thereof. This operation is time-consuming and objectionable by reason of the fact that transfer often occurs to the hands and to the clothes of the operator.

Because of the oily and viscous nature of the ink composition, difliculty is sometimes experienced in adhering the ink composition to the surface of the fountain roller in a manner necessary to achieve and to maintain the desired continuous feeding relation. Under such circumstances it is necessary to make use of special devices or forcibly to apply the ink onto the ink roller in order to maintain the desired feeding relation.

To regulate the flow of ink in a manner to supply an amount to maintain copy take-off requirements across the width of the plate has, in the past, required the use of highly skilled operators which increases the cost of operation and also increases the number of persons re- 2 quired to maintain the press in operation to produce copy of acceptable quality.

in present systems Where printing occurs in limited areas across the plate, it is customary to block out the ink feed in sections corresponding to the non-printing areas to avoid ink feed thereto. This attempt to limit feed of ink to non-printing areas is defeated by the subsequent inking operations wherein the reciprocating rollers spread the ink composition laterally over adjacent surfaces to areas where no ink is needed or desired. As a result, considerable skill is required in operation to maintain a desired balance between ink supply and copy produced therefrom.

There are a number of other objectionable features not specifically enumerated and it is an object of this invention to produce an inking system which is substantially free of the objectionable features characteristic of present inking devices.

An object of this invention is to provide an inkling system wherein the ink supplied to the inkingv rollers is always fresh and free from dirt, lint and other foreign matter.

Another object is to produce an inking system of the type described whereby the amount of labor required for cleaning up the elements after the production of copy and toload the elements at the start of operations is markedly reduced and it is a related object to provide an inking system wherein the requirement for skilled labor is at a minimum.

A further object is to provide an inking system of the type described wherein the desired distribution. of the ink composition over the inking rollers can be achieved without or else with. a lesser number of oscillating and inking rollers in the ink feed system.

A still further object is to produce an inking system of the type described embodying simple means for effecting color change or embodying means whereby more than A one color may be fed to the printing member at the same time.

A still further object is to produce an inking system wherein adjustment of the amount of ink supplied to various portions of the inking rollers may be achieved in a simple and eficient manner to give positive control and in which the application of ink can be limited to within certain areas of the inking rollers for applica tion onto the inking plate without lateral spread of substantial amounts of ink to areas wherein the requirements therefor are at a minimum or absent.

A still further object is to provide a new and improved inking system which is rugged in construction and simple in operation whereby highly skilled technicians are not required for operation and in which inking may be limited to predetermined areas thereby to permit full control 7 of the amount supplied for copy requirements.

A still further object is to provide an inking system wherein ink distribution for minimum copy requirements can be achieved without the use of oscillatingrollers for spreading the ink transversely across the inking rollers whereby ink in the desired amounts can be accurately measured onto certain areas without displacement to adjacent areas and thereby to eliminate the need for highly skilled operators for the production of copy of good quality.

These and other objects and advantages of this invention will hereinafter appear and for purposes of illustration, but not of limitation, an embodiment of this invention is shown in the accompanying drawings in which Figure 1 is an elevational view in plan of an inking system embodying features of this invention;

Figure 2 is a top plan view partially in section of the inking system shown in Figure 1;

Figure 3 is a sectional elevational view taken along the line 3-3 of Figure 1, and

Figure 4 is a sectional elevational view taken substantially along the line 4-4 of Figure 3.

For purposes of illustration, description herein will be made to a lithographic duplicating machine having an ink system embodying features of this invention for supplying ink to the surface of a lithographicplate mounted on the periphery of a rotating drum 11. It will be understood that inking systems of the type described may be assembled for use in combination with other printing elements for the production of inked copy.

As shown in Figure 1, ink is transmitted to the plate 10 by a series of inking rollers 12, 13 and 14 joined to each other by intermediate rollers 15 and 16 whereby ink applied to the first roller 14 is transferred from roller to roller to the end that the ink composition becomes uniformly distributed circumferentially about the rollers before it is taken otf by the last roller 17 for transfer to the printing plate 10. To the present, description has been made of a conventional assembly for transferring ink in uniform distribution to a printing plate except for the presence of oscillating rollers provided to secure lateral distribution in prior arrangements and which may be displaced by rotating rollers 15 and 16 for reasons which will hereinafter be described without handicapping the distribution of the ink composition.

An important concept of this invention resides in a new and improved ink supply system for delivering ink composition at a predetermined rate to roller 14. The ink feed comprises an accumulator 20 operating under predetermined gas pressure for forcing ink compositionintroduced into the housing 21, as by a pressure gun, piston like cupped container, or the like, through an outlet 22 into a flexible tubing 23 in communication with a control valve 24 and shutting off or limiting the passage of ink through the tubing. A pressure gauge 25 is connected in the tubing between the accumulator and shut-off valve to indicate the force under which the ink composition is maintained within the tubing.

While various means may be provided for directing the ink flowing through the stop valve 24 onto the inking roller 14, an important concept of this invention resides in a system whereby the ink composition is supplied directly to the surface of the inking roller by means for i,

placing a predetermined amount of ink thereon responsive to rotation of the roller in operation.

In accordance with the practice of this invention the means for supplying ink to the roller in response to opera tion thereof comprises a ball applicator supported in position of use by a bracket 31 having a cleat 32 which maintains a gripping relation with a traversing mechanism which will hereinafter be described. An opening 33 is provided in the turned upper end portion of the bracket through which a thumb screw 34 extends in threaded engagement for adjustment of the bracket relative the inking roller. The ball applicator, secured as by a screw. 35 to the lower end of the bracket 31, comprises a cylindrical block 36 having an inlet 37 at one end in communication with tubing 38 leading from the stop valve 24.

Another opening 39 in the forward end portion of the block and in communication with the inlet 37 provides a seat for a coupling member 40 having an opening 41 extending therethrough. The rearward portion of the coupling member is of smaller diameter and threaded about its outer surface 42 for engagement in the opening 39 in the block 36 while the forward end portion 43 of larger diameter is threaded for receiving a nose piece 44 in threaded engagement thereon. Located within the opening 45.defined by the nose piece and the cavity 46 of increasing cross section in the forward end portion of the coupling and into which the opening 41 terminates is a ball member 47 having a diameter greater than the openwithin the defined opening while an arcuate portion thereof extends beyond the nose piece in contacting relation with the peripheral surface of the first inking roller 14.

A plurality of ball applicators of the type described may be arranged in laterally spaced apart relation for applying ink to separate portions of the inking roller. Each ball applicator may have its own valve for control of ink composition thereto or else they may be connected in groups with a single valve control for applying ink composition adjusted in amounts according to the central control.

Although use may be made of a ball member having a perfectly spherical surface with which the ink is carried during turning movement from the socket to the surface of the inking roller contacted by the ball, improvement in the smoothness and in uniformity of feed is secured by the use of a novel ball member having a plurality of grooves formed in the spherical surface with the grooves arranged in angular relation to one another so that at least one groove is always in position to provide a passage between the cavity or socket in which the ballis operating and the exterior thereof. It has been found that the existence of a through passage of the type described relieves surges in pressure heretofore occasioned by the presence of air bubbles in the line or by variation in forces operating to urge the ink composition through the line.

In operation, printers ink, generally viscous in character, is pumped through a check valve or the like into the base of the accumulator 20. From the accumulator. the ink composition is forced under constant pressure determined by the discharge pressure of the accumulator through the tubing 23 to the stop valve 24 which can be adjusted to permit a predetermined and accurately controlled rate of flow of the ink composition to the ball point feed member 30. During rotational movement of the inking roller 14, the ball member 47, preferably loosely contained within the socket and urged into contacting relation with the surface of the roller by adjustment of the supporting bracket 31, is actuated by frictional force to roll within its socket and transmit ink from the socket to the ink roller.

It will be apparent from the description that in the system of the type described ink is applied directly to the peripheral surface of the roller in amounts which may be controlled by adjustment of the valve member 24 precisely to maintain copy take-off requirements. Where a plurality of ball applicators are provided for feeding ink to the spaced apart portions of the roller, it is possible by means of this simple but positive adjustment to vary the flow 'of ink composition to selected portions of the roller thereby expediently and effectively to measure the precise amount of ink required to effect the desired printing operations,

Control of thischaracter may be effected in devices of the type described and claimed herein withoutthe necessity for highly skilled or expensive labor.

It will be apparent also that until the ink composition is applied by the applicator to the surface of'the inking roller, the ink composition has not been exposed to the atmosphere and is incapable of being contaminated with dust, lint or other foreign matter or incapable of variation in solids content or viscosity as is generally experienced in prior systems because of evaporation of diluents or the like from the exposed ink composition. In addition, no ink remains in open reservoirs or fountains to be discarded when the printing operation has been completed with the result that considerable savings is experienced in materials.

When cleaning up at the end of the printing operation or for change in color, instead of having to remove the remaining ink composition from the fountain and cleaning the ink composition from the doctor blades, ductor rollers and the like as well as the distributor rollers, it is only necessary in the structure described and'claitned herein ing in the nose piece whereby the ball is free to rotate 7-} to clean the distributor rollers. This is a relatively simple and clean operation compared to the steps which have heretofore been required and permits considerable savings in time and labor as well as conservation of ink composition. It will be apparent from the description that the inking device may be readily mounted and disengaged from the machine to facilitate cleaning, repair and replacement.

To the present description has been made of a new and improved ink feed system providing means for feed ing ink composition and adjusting the flowof the ink composition to give calculated control of the amount of ink supplied to the inking rollers and means operative in response to movement of the inking rollers for positive displacement of an amount of ink calculated precisely to maintain copy take-oif requirements. The described systern applies the ink directly to the inking roller thereby to avoid the possibility of non-uniform flow which has been experienced in prior processes because of the inability of the ink composition under certain circumstances to wet out the fountain roller or the inking rollers.

Description will now be made of a new and novel device forming a part of the inking system described and claimed herein whereby the ball applicator or other ink applicator is caused to rove back and forth across the surface of the inking roller Within predetermined limits to apply the ink composition in uniform concentration and in a spiral pattern onto the surface of the roller.

As shown in the drawings, the rover mechanism which causes the ink applicating means to shift back and forth across the surface of the inking roller during operation comprises a roller 5i) of cylindrical shape supported on shaft 51 mounted at each end in suitable bearings 52 provided in depending arms 53 of a yoke member 54. The yoke is suspended at an intermediate point from the lower end portion of a pivot post 55 which extends upwardly through an opening in a swivel frame member 56 and through a spacer bushing 5'7 into one end portion of a horizontally disposed swivel arm 58 to which it is connected by a pin 59. Thus as the arm 58 swings in a horizontal plane, the post 57 and associated yoke 54 with its supported roller 50 is caused to turn about the axis of the post.

Another cylindrical roller 60 spaced from the first by an amount corresponding to the distance between inking roliers 13 and 14 is similarly supported for rotational movement on a shaft 61 mounted at its ends in suitable bearings 62 provided in depending arms of a separate yoke 63. The yoke is suspended at its midpoint from the lower end portion of a pivot pin 64 which extends upwardly through an opening in the forward end portion of the swivel frame member 58 in which it is mounted for free rotational movement about a horizontal axis. Tie rods 65 are pivotally joined to the upper end portions of the yoke members operatively to interconnect the yoke members to effect conjoint pivotal movement. about their horizontal axes.

The extent of turning movement of the rover roller supporting yokes 63 and 54 is determined by an adjustable stop 66 depending from an intermediate portion of the connecting rod 65 between stop blocks 67 depending from the frame member. I

The frame member from which the rover rollers are pivotally suspended has a rearwardly extending portion 68 in the form of a yoke having arms 69 and 70 depend ing therefrom. A trolley bar 71 extends through aligned openings 72 in the lower end portions of the arms 69 and 70 to permit the swivel frame member freely to rock about the trolley bar while also permitting the frame to shift freely in either direction transversely along the bar. A shaft 73 located on the trolley bar between. the depending arms supports the bracket 31 in a manner to provide for lateral shifting movement thereof with the frame but independent of its rocking movement.

The trolley bar 71 mounting the frame member and bracket is rigidly supported at its ends in sleeves 74 fixed rollers, means are provided for adjustment of the trolley bar relative its supporting frame elements. As shown to upper end portions of supporting plates 75 having slotted openings 76 through which fastening screws 77 extend to lock the plates in fixed position on side frame members 78 and 79 of the printing machine.

In order to permit a desired operative engagement to be effected between the rover rollers and the inking in Figure 3, the desired adjustment can be effected by means of a screw bolt 89 which threadedly engages an extension 81 rigid with the frame member and extends therethrough to engage the underside of a flange 82 extending outwardly from the lower end portion of the supporting plate 75. A lock nut 83 is provided to prevent movement of the adjusting screw from desired position and the plates are held in their adjusted position by tightening down on screw members 77. The slotted portions 76 provided in the plates 75 permit the amount of vertical adjustment necessary to effect the desired operative relation between rover rollers and printing rollers.

Positioned to extend upwardly into the path of the rearwardly extending portion of the swivel arm 58 are a pair of spaced stop pins 84 and 85 which extend upwardly from brackets 86 laterally slidable on a stop bar 87 fixed between side frame members 78 and 79. The brackets 86 are secured in adjusted position along the stopbar 87 by thumb screws 88 which extend through openings in thebracket operatively to engage the bar to effect a desired gripping relation.

A tension spring 89 is anchored at one end about a pin 90 extending upwardly from an intermediate portion of the swivel arm 58 while the other end is anchored onto a pin 91 extending upwardly from post 64. The tension spring 89 operates constantly to urge the swivel arm 58 into one direction or the other between positions of adjustment determined by a yoke 92 having spaced depending arms 93 and 94 between which the swivel arm 58 extends. The yoke 92 is fixed onto an end portion of a lever arm 95 which is operatively mounted for conjoint turning movement onto an end portion of the swivel post 55.

Having described the construction of the rover mechanism, illustration will now be made of its operation for automatically shifting the ink applicators back and forth over the inking rollers to supply ink composition in a spiral pattern over the surfaces thereof during rotational movement.

In operation, the rover rollers are positioned at a slight angle with the. inking rollers against which they are constantly urged by gravitational force. As the inkingrollers turn during normal operation, turning movement is simultaneously transmitted by frictional force to the rover rollers in contacting relation therewith. Because of the angular relation between the inking rollers and the rover rollers, the latter are actuated transversely in the direction of. oifset whereby the entire rover frame assembly is caused to shift laterally on its trolley bar until the lever arm 58 is engaged by one or the other of the stop pins 84 and 85. Upon engagement, further movement ofthe rover frame causesv the swivel arm 58 to rock about its pivot until pin 90- positioned on an intermediate portion thereof shifts to the opposite side of the line formed by the pivot pins 55 and 64. When the arm shifts beyond alignment, the spring force functions to shift the swivel arm 58 to its other position of adjustment as determined by the arms 93 and @4 depending from yoke 92.

Conjointly with the swinging movement of the swivel arm, swivel pin 55 is turned about its axis whereby the angular relation of the rover roller becomes offset in the opposite direction with respect to the inking rollers and causes the rover frame thereafter to shift laterally in the opposite direction until similar engagement is effected. between the swivel arm and the other of the stop pins. Turning movement of the first yoke 54 supporting the rover roller 50 is transmitted directly to the other rover roller by means of connecting rods 65.

The rover rollers are adapted to shift back and forth in the manner described during operation of the machine between two angular positions of adjustment, the extent of which is determined by the relationship between stops 66 and stop bars 67. The angular relationship between the rover rollers and the inking rollers as determined by the cooperating stop members described controls the rate of lateral movement of the rover mechanism during normal operation.

It will be apparent from this description that the movement of the rover mechanism and its associated ink applicator or applicators can be limited to a predetermined pattern with respect to the extent of movement by selectively positioning the stop bars 84 and 85 and in the rate of movement by adjusting block 66 which controls theangular relation between the roving rollers and the inking rollers.

In addition to causing the ink applicators and forth along the ink rollers as described, the rover performs an important function in distributing the ink composition over the area selected for inking without causing it to spread to areas where ink is not desired. This back and forth motion of the rover aids in spreading the ink first by providing a rolling action having a component along the length of the ink roller as well as around its circumference and secondly, by picking up ink composition in areas where it is in excess and depositing it in areas where there may tend to be a deficiency. Since the area traversed by the rover is controllable, as described above, it does not spread ink into areas outside of these limits. The spreader rollers used in common practice contact the inking rollers throughout their entire length and reciprocate over a relatively short range;

Their action, therefore, makes it impossible to establish a clear line of demarcation between areas where ink is desired and those where it is not desired. The controlled spreading action accomplished by the rover makes it unnecessary to use reciprocating spreader rollers of the conventional type and in addition permits the use of a lesser number of inking rollers to obtain proper distribution of the ink.

It will be understood that spreader rollers reciprocating back and forth in the usual manner may be employed in the inking system and it will be further understood that the inking mechanism described is subject to various modifications with respect to parts, their arrangement and assembly and that such mechanism may be used in connection with other printing machines without departing from the spirit of the invention, especially as defined in the following claims.

I claim:

1. An inking system of the type described having ink distribution rollers comprising an ink applicator including a ball point member, means for supporting the ink applicator with the ball point in surface contact with an inking roller wherebyfrictional forces become operative to cause turning movement of the ball responsive tooperation of the roller, means for causing the ink. applicator to reciprocate crosswise of its support relative theinking roller between two predetermined positions of adjustment during rotational movement of the roller to apply the ink in a spiral patternon the surface of the inking roller, and means for supplying ink at a predetermined rate under pressure to the ball point member.

2. An inkingsystem of the type described having distribution rollers comprising an ink applicator for directing a line of ink onto the surface of an inking roller, a support upon which the ink applicator is mounted for sliding movement in parallel relation relative the inking roller, an operative connection between the applicator and the inking roller for causing the applicator to reciprocate on its support crosswise relative the inking roller. in response'to rotational movement of the inking roller to to move back apply a spiral line pattern of ink to the surface of the inking roller, and means for supplying a predetermined quantity of ink under pressure to the ink applicator.

3. An inking system of the type described having dis tribution rollers comprising an ink applicator for directing a line of ink onto the surface of an inking roller, a support upon which the inking roller is mounted for relative crosswise movement parallel to the inking roller, means responsive to rotational movement of the inking rollers for causing the ink applicator to reciprocate crosswise on its support between two positions of adjustment including a rover roller mounted for free rotational movement in an axis parallel with the inking roller and for turning movement about an axis normal to the inking roller between two positions of offset, means for positioning the rover roller in operative engagement with the inking roller whereby the rover roller is caused to rotate and shift laterally when offset from the inking roller, means for shifting the offset of the rover roller relative the inking roller at predetermined spaced apart positions to cause the rover roller to shift back and forth between two predetermined positions of adjustment during rotational movement of the inking rollers, an operative connection between the rover roller and ink applicator for movement of the latter conjointly with the rover roller crosswise of the inking roller and means for supplying a predetermined quantity of ink to the ink applicator.

4. An inking system of the type described having ink distribution rollers comprising an ink applicator for directing a line of ink onto the surface of an inking roller, a supporting member means responsive to rotational movement of the inking roller for causing the ink applicator to rove crosswise of the inking roller between two positions of adjustment including a housing mounted on said supporting member for shifting movement crosswise of the inking roller, a rover roller mounted on the housing for rotational movement about an axis parallel with the inking rollers and for turning movement normal to the inking roller between two positions of offset, means for positioning the rover roller in operative engagement with the inking roller whereby the rover roller is conjointly rotated and caused to shift with its housing crosswise over the inking roller when offset, means operative during crosswise movement of the rover roller to shift the rover roller in the opposite offset whereby the rover roller is caused to move in the opposite direction responsive to continued rotational movement of the inking roller, said latter means including stops positioned in spaced apart relation to limit movement of the rover roller between two determinable positions of adjustment, means forming a part of said housing for carrying the ink applicator in crosswise movement therewith and means for supplying a predetermined quantity of ink to the ink applicator.

5. An inking system of the type described comprising an ink applicator for directing a line of ink onto the surface of an inking roller, a supporting member means responsive to rotational movement of theinking rollers for causing the ink applicator to reciprocate crosswise of the inking rollers between two positions of adjustment, said means including a housing mounted on said supporting member for shifting movement crosswise of the inking rollers, a pair of rover rollers suspended from the housing for rotational movement about an axis parallel with the inking rollers and for turning movement about an axis normal to the inking rollers between two positions of ofiset, means for positioning the rover rollers in spaced apart relation for operative engagement with the separate inking rollers, means interconnecting the rover rollers for effecting conjoint turning movement about the axis normal to the inking rollers, means adapted operatively to be engaged during crosswise movement of the rover rollers to effect turning movement thereof to an opposite offset whereby the rover rollers and attached housing are caused to shift crosswise between the two determinable stop positions, means forming a part of said housing for carrying the ink applicator in crosswise movement therewith, and means for supplying ink under pressure to the ink applicator.

6. An inking mechanism as claimed in claim 4 in which the housing is mounted for rocking movement about an axis parallel to the inking rollers for bringing the rover rollers into and out of engagement with the inking rollers.

7. An inking mechanism as claimed in claim 4 including adjustable means for limiting the degree of offset of. the rover rollers.

8. An inking mechanism as claimed in claim 4 which includes spring means constantly urging the rover rollers to one or the other of their offset positions.

9. An inking mechanism as claimed in claim 4 including means for adjusting the housing relative the inking rollers to effect operational engagement of the rover rollers therewith.

10. An inking system of the type described having ink l0 wise of the inking roller and for rocking movement in a plane normal to the inking roller, a rover roller supported by the housing for rotational movement about an axis substantially parallel with the inking roller and for turning movement about an axis normal to the inking roller and substantially perpendicular to the plane in which the housing is rockable thereby to permit the rover roller to be rocked with the housing into operative en-- gagement with the surface of the inking roller, means operative at predetermined spaced apart positions to shift the rover roller to one of its offset positions during crosswise movement in one direction and to another of its offset positions during crosswise movement in the other direction whereby said rover roller is caused to shift back and forth between two predetermined positions of adjustment and to spread the ink about the surface of the inking roller during such operational engagement therewith.

References Cited in the file of this patent UNITED STATES PATENTS 701,221 Ray May 27, 1902 878,651 Mascord Feb. 11, 1908 1,808,815 Hervey et a1. June 9, 1939 

